But even if Newton plays a series against the Steelers, Panthers coach Ron Rivera says the team won’t have a complete read on Newton and his surgically repaired shoulder until the start of the regular season.

“I think he’s still taking steps. You really won’t know until the opener. That’s just the way it is,” Rivera said Tuesday. “Nobody knew what he was going to be like his rookie year. That’s kind of how this is going to be. You won’t know until we open up in San Francisco.”

Newton missed OTAs and minicamp as a rookie in 2011 because of the lockout. He went on to break Peyton Manning’s rookie passing record (now held by Andrew Luck) and win Offensive Rookie of the Year honors.

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But that situation was different in that Newton was six years younger and wasn’t coming off shoulder surgery.

Newton, 28, has been progressing steadily since he was shut down for 12 days during training camp after developing pain in the shoulder. He played the opening series last week in Jacksonville, completing his only two pass attempts for 21 yards and a touchdown.

He has appeared to be throwing without limitations at practice the past two weeks.

After the game at Jacksonville last week, Newton said he couldn’t put a percentage on where his arm strength is, but added that he feels “great.”

Rivera said if that lone series against the Jaguars turns out to be the extent of Newton’s preseason work, he’s OK with it.

“You do what you have to do. I think he’s on track. He’s done some good things,” Rivera said. “But you wake up every morning just wanting to make sure he’s fine. He’s done everything we’ve expected so far. So as we’re going forward, we’ll see.”